Aggressive blood pressure lowering may cause kidney damage

Liz Meszaros, MDLinx | August 02, 2017

Aggressive combination treatments for hypertension using renin-angiotensin system (RAS) inhibitors may actually damage the kidneys instead of protecting them, according to researchers from the University of Virginia School of Medicine, Charlottesville, VA, who published their results in the journal Science.

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RAS inhibition for hypertension

Blocking renin-producing cells from producing renin in adult mice caused obstructive vascular lesions to form in the kidneys.

“To treat hypertension, people use inhibitors of the RAS,” explained R. Ariel Gomez, MD, director, UVA’s Child Health Research Center. “They’ve been in use for quite a bit now, and, for the most part, they’re safe. Our work in mice indicates that complete lack of renin results in vascular lesions. The question is whether aggressive, long-term use of compounds that completely ablate the renin angiotensin system causes any problems in humans. Thus, additional research is needed.”

The body produces renin to regulate blood pressure, but renin-producing cells also have a vital role in the formation of vasculature during fetal development in the womb. During pregnancy, renin inhibition is contraindicated because of these deleterious effects.

In this study, Dr. Gomez and colleagues found that blocking renin-producing cells from producing renin in adult mice caused obstructive vascular lesions to form in the kidneys. They hope to further study whether blocking renin-producing cells, especially over long periods, has unintended side effects in hypertensive patients.

In the meantime, however, they stressed that patients should not stop taking their prescribed medications.

“Is the secret to stop using these medications? No,” said Dr. Gomez. “But we need to find out several things. First, whether it is necessary or not to use dual combinations of drugs that over-activate renin cells…and also, how low and how fast should blood pressure be lowered. And then, after that, is to look at the effects this combination [treatment] has in individuals, in people.”

In the future, Dr. Gomez and colleagues plan to look specifically at the less common combination treatments that completely block the RAS system, and chronically stimulate renin cells to accumulate and dramatically change the structure of the kidneys.

“What we need to find out is, how does this happen? So we can understand what molecules are activated, and maybe act on those molecules and use lower doses to prevent the overgrowth of the vessels,” he explained.

“I think the most important thing is to have good judgment as a doctor and not to overdo it. Learning this is useful, but we need to find out more,” Dr. Gomez concluded.

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